The present invention broadly relates to removing flocks from fiber bales and pertains, more specifically, to a new and improved method of extracting fiber flocks from fiber bales by moving an extraction or opening member, preferably a spiked or toothed opening roller or roll provided with tooth-like spikes or teeth, over an extraction or removal surface of fiber bales serially disposed in a row on a supporting surface. The extraction member is part of a bale-opener machine and rotates about an axis of rotation, and the tooth-like spikes of the spiked or toothed opening roller extract fiber flocks from the extraction or removal surface and deliver the fiber flocks to a flock transportation means. The fiber bales arranged in a row having a predetermined longitudinal direction are moved by steps or increments toward the bale-opener machine for further fiber-flock extraction. The present invention also relates to a new and improved apparatus for extracting fiber flocks from fiber bales.
In a spinning mill, the supplied fiber bales are first unwrapped or stripped of their packaging or the like and then directly delivered to an opening or cleaning room in which the fiber bales are opened or loosened into fiber flocks.
This opening operation was carried out in an early generation of bale-opener machines in that spinning-mill personnel opened the fiber bales in layers and placed the layers on a conveyor belt or band for delivery to a layer-opening apparatus, which in most cases was a lattice apron.
The operating personnel also fulfilled the task of proportionally extracting fiber layers from a plurality of different fiber bales according to a predetermined proportion or ratio and, furthermore, of layering these extracted different fiber layers one upon the other, so that the layer-opening apparatus was supplied with a fiber-flock mixture to be opened.
However, this former method of bale opening had the disadvantage that the fiber-flock mixture was very inaccurate and, moreover, was dependent on the work discipline or dexterity of the operating personnel.
A further disadvantage of this former method is seen in the fact that the outer fiber layers of the fiber bales possess a substantially looser coherence or compactness than the inner fiber layers of the fiber bales, with the result that the inaccuracy of the fiber-flock mixture was even increased to a greater extent due to variations in the density or compactness of the individual fiber-flock layers.
Such disadvantages and quality problems called for the provision of an extraction method which is more accurate and less dependent on manual labor. A substantially improved method of, and apparatus for, extracting fiber flocks is disclosed, for example, in Swiss Patent No. 503,809, published Apr. 15, 1971.
In this prior art apparatus for extracting fiber flocks from fiber bales, the fiber bales are serially disposed in a row on the supporting surface of a conveyor belt or band and opened by a substantially horizontal fiber-extraction member which is perpendicularly oriented to the row of fiber bales.
In an embodiment of this prior art apparatus disclosed in the aforesaid Swiss Patent No. 503,809, the fiber-extraction member is movable on tracks along the row of fiber bales in such a manner that the so-called extraction or removal surface of the fiber bales, within which the fiber flocks are extracted, is not parallel to the aforesaid support surface of the conveyor belt or band. In other words, the extraction surface forms or defines a so-called angle of inclination with the supporting surface.
Since the extraction member is always moved back and forth in the same path of travel, it is thus achieved that the fiber bales can be advanced by means of a conveyor belt or band such that a predetermined bale stock or supply can be stored on the conveyor belt or band.
A disadvantage of this prior art bale opener is that only a small and limited number of different bales, i.e. bales of different provenances or origins, can be simultaneously opened, so that only a limited number of fiber bales per conveyor belt or band is available for the fiber-stock mixture. Consequently, it is necessary to provide several parallel operating bale-opener machines in the event of mixing fiber flocks from a larger number of fiber bales, for example, ten fiber bales.
This disadvantage was overcome by a later generation of bale-opener machines comprising a fiber-extraction member which likewise contains a substantially horizontal extraction roller which is perpendicularly oriented to a row of fiber bales. This flock extraction roller moves to-and-fro over the surface of serially arranged stationary fiber bales and thereby extracts or loosens fiber flocks from the extraction surface of the fiber bales, the extracted fiber flocks being delivered to flock transportation means. Such a bale-opener machine has been marketed world-wide under the trademark "UNIFLOC" by the assignee Rieter Machine Works Limited, located in Winterthur, Switzerland and is disclosed, for example, in European Patent No. 093,235, published July 3, 1985 and the cognate U.S. Pat. No. 4,566,152, granted Jan. 28, 1986.
However, this improved method of removing flocks from fiber bales described in the aforesaid European Patent No. 093,235 and the cognate U.S. Pat. No. 4,566,152 still is associated with the disadvantage that, for a given extraction or penetration depth of a flock removal member, a different or variable extraction performance is achieved during each pass over the fiber bales depending on the height of the latter, since the density or compactness of the fiber flocks in the outer bale layers, i.e. in the upper and lower bale regions, is substantially lower than in the inner bales layers, i.e. in the middle bale region.
This disadvantage or drawback was eliminated by a method of and a control arrangement for a machine for extracting fiber flocks from textile fiber bales as described, for example, in European Patent Application No. 0,193,647, published Sept. 10, 1986 and the cognate U.S. Pat. No. 4,660,257, granted Apr. 28, 1987. According to this prior art method, the penetration depth of the extracting member into the bales is gradually reduced while operating in an upper bale region during a predetermined number of passes from a predetermined maximum value to a lesser penetration depth value predetermined for a middle bale region. The penetration depth is then maintained constant at the lesser penetration depth value while operating in the middle bale region. Finally, the penetration depth is gradually increased while operating in a lower bale region to a maximum penetration depth. The lowering of the extracting member in discrete increments having magnitudes determined by gradually reducing or increasing the penetration depth is effected by a suitable automatic control unit.
However, a disadvantage of the method of extracting fiber flocks by means of an extracting member moving along a row of fiber bales is seen in the fact that the stock or supply of further fiber bales has to be provided as a second row of bales arranged in parallel or in series to the first row of fiber bales being momentarily processed. In the case of a parallel arrangement of a second or reserve row of fiber bales, there would be required a turret mechanism containing the extracting member rotatable through an angle of 180.degree..
In a further method of, and apparatus for, mixing and opening fiber bales disclosed, for example, in German Patent No. 1,193,844, published May 26, 1965, individual layers of raw or crude fiber bales to be mixed are layered one upon the other to form a square-shaped pile which is horizontally conveyed between two lateral needle-type conveyor belts and between an upper needle-type conveyor belt and a lower needle-type conveyor belt toward an extraction carriage comprising two substantially vertical spiked opening rollers and moving horizontally to and fro over the entire front surface area of the layer pile, the thereby extracted fiber flocks being delivered in free fall to a further opening apparatus.
The disadvantage or drawback of such a bale-opener machine is the requirement of supplying a pile of different layers which can only be provided in an inaccurate mixing proportion or ratio.